1: \(=3\left[16x^2y^2-\left(x^2-2xy+y^2\right)\right]\)
\(=3\left[\left(4xy\right)^2-\left(x-y\right)^2\right]\)
\(=3\left(4xy-x+y\right)\left(4xy+x-y\right)\)
3: \(=4\left(x^4+x^2y^2-2y^4\right)\)
\(=4\left(x^4+2x^2y^2-x^2y^2-2y^4\right)\)
\(=4\left[x^2\left(x^2+2y^2\right)-y^2\left(x^2+2y^2\right)\right]\)
\(=4\left(x^2+2y^2\right)\left(x-y\right)\left(x+y\right)\)
4: \(=-\left(x^2+2x-15\right)=-\left(x+5\right)\left(x-3\right)\)
5: =(x-1)(3x-1)